The path of the old elevated highway near the FleetCenter will be completely filled in with up to 1 million square feet of mixed-use development. The buildings will have a maximum height of 100 feet.

A 125,000-square-foot, five-story YMCA whose design has not yet been completed, straddling the entrance and exit ramps to the Big Dig. North End residents pushed for it after another community center closed.

Existing parking garage encases ventilation stacks, with retail and office space on the ground floor and the MBTA's Haymarket Station underground.

A total of 2.8 acres designed by Crosby, Schlessinger & Smallridge and Gustafson Guthrie Nichol Ltd. Construction, with an $8 million budget, begins in the fall on two rectangles of lawn, gardens, a canal-like strip of water, and a pergola. The Freedom Trail will run through it, but critics wonder how inviting the small parks will feel to people beyond the neighborhood.